QuFresh vs ERV
I’m at the stage in my build where I have to make final decisions on HVAC and other mechanicals. I’m building a 2 story (1200 down, 890 up), house as tight as I can afford/get my builder to execute. Goal is < 1.5ACH50. The builders HVAC guy has initially suggested Carrier Comfort, 2 ton, 2-stage systems…one for up and one for down….with a QuFresh instead of an ERV.
That seemed like a whole lot of unit to me, even with the two stage compressor. I’ve asked to at least use the Carrier Greenspeed Intelligence (true) variable speed units. Is that still too much? I”m about to ask to see Manual J calculations, but that also seems like being a bit of a jerk I suppose. Is it?
Also, thoughts on the QuFresh vs an ERV? HVAC guy said the QuFresh was more bang for your buck. How much of a difference in cost are we talking? $1k? Is it worth the ERV vs the QuFresh?
I feel like I have a good conceptual understanding of HVAC needs, but without “seeing the work” from the HVAC guy, I’m not sure if what I’m getting is sized right and ventilated properly. Last thing I want is oversized units.
Help!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
You probably want to do your own manual j, or pay a professional to do it. HVAC contractors notoriously often just fudge the inputs so that it spits out what they ball parked in advance, if they bother with it at all.
The QuFresh is just a fan. $500 for a fan doesn't seem like good bang for the buck to me. Especially in zone 6, fresh air with no energy recovery is just stupid. Hard pass on that suggestion.
Thanks for the feedback. It's confirmation for me to push a little. I had specified in our contract w/the builder that the HVAC contractor would do a Manual J...but good point about them basically confirming their advanced ballpark guess.
I'll probably just run my own tonight Could get the HERS rater to run it for a couple hundred bucks. But...what fun would that be (and in advance, I'm pretty comfortable using some of the online softwares to do it...I develop heat transfer models for a living...though if anybody has recommendations for a better online tool to use, I'm all ears).
Thanks for the opinion on the QuFresh. I was a little skeptical when he brought it up, but I told him I'd do a little research. Haven't been able to find much. I'm not nearly as cold as Zone 6 (right on the edge of Zone 3/4), but yeah, the thought of sucking in 96 degree humid air in summer, or 20 degree air in winter seems unappealing to me.
Sorry, I don't know where I got the idea you were in zone 6, must have read another post in between reading yours and posting a reply.